Question

Given $M=(0,1,2)$ and $N=(1,2,3)$. Find $(M\cup N)\times (M-N)$

Answer 1

Union of two sets has all the elements of both the sets.
So, $M\cup N=\{0,1,2,3\}$
$N-M$ means subtracting the common elements of $M$ and $N$ from $N$.
So, $N-M=\left\{3\right\}$
Cartesian product of two sets is found by forming ordered pairs, where $x$-coordinate is from first set and $y$-coordinate is from second set.

So, $(M\cup N)\times (N-M)=\left\{\right(0,3),(1,3),(2,3),(3,3\left)\right\}$